BookReader — What you read finally stays with you

We've all found ourselves staring at a paragraph.

Reading it for the third time. Understanding every word and none of the ideas.

Now the page answers back.

Ask about whatever you don't understand, the way you'd actually ask. The agent knows the whole book, knows your goal, and explains it at your level, until it clicks.

It makes nothing up. Everything comes from the book.

Every explanation carries its citation. Tap it and verify it in the book, word for word.

7 · Transactions

This pattern of read-modify-write can cause lost updates. An atomic compare-and-set operation avoids the lost update by only allowing the write if the value has not changed since you last read it.

243

p. 243 · Transactions — tap and verify

Cited review

Reading is half of it.

What matters becomes flashcards. They come back to you right before you'd forget. And each one remembers which page it came from — in case you want to reread it.

It's a real card. Try it.

Your books are yours. So are your questions.

No account. No server. Nobody in between. Everything lives on your device, and you can take it with you anytime.

Private by design. That's BookReader.

Everything in the box.

The whole toolkit, grouped by the moment you need it — nothing buried in menus.

While you read

Immersive mode, page by page or continuous scroll.
In-book search, bookmarks, highlights & notes.
Three reading themes, paper tones, brightness & warm light.
Typography tuned your way: font, size, columns, line height.
Remaining reading time, per chapter and per book.

When something doesn't click

Ask the agent: it knows the whole book and your reading goal.
Select a passage: «Explain this», «Why it matters», «With numbers».
Zone: circle a figure or equation, get it explained (PDF).
Every answer cites its page — tap and verify.
Feynman mode: you explain it, the book checks you.

To make it stick

Flashcards from the book, with spaced repetition.
Study mode with streaks, across books and shelves.
A recall question when you finish each chapter.
Notebook templates; export to Anki & Markdown.
An honest analysis of what you really read.

Offline & yours

Prepare for offline: read and ask the book on the plane.
Installable PWA — reading, highlighting, reviewing without connection.
Sync between devices via your own Google Drive.
Full backup, export anytime. No account, ever.

How much does it cost?

The app is free. The agent runs on your own AI key (BYOK): you pay your provider only for what you use — no middleman, no subscription.

What formats does it read?

EPUB and PDF. The agent reads both equally well: same chat, same citations, same flashcards.

Can I ask in a different language than the book?

Yes. Read in English and ask in Spanish, or the other way around: the agent understands your question, searches the book and answers in your language, citing the original passage.

Which AI can I use?

Any provider with an OpenAI-compatible API: set the URL, your key and whichever model you want. Without the agent, BookReader is still a complete reader.

Where are my books stored?

In your browser's storage, on your device. They are never uploaded anywhere. You can sync annotations through your own Google Drive and export a full backup anytime.

Are the agent's answers reliable?

The agent answers from passages of the book and cites every claim. The citation is your verify button: one tap and you're on the page. If the book doesn't cover something, it says so instead of filling in.

Does it work offline?

Reading, highlighting and reviewing cards: yes, it's an installable PWA. The agent needs a connection to talk to your AI provider.

The next book you read, you keep.

Open BookReader

Free. No account. In your browser.